Holocene palaeoclimate in the northern Sahara margin (Jefara Plain, Northwestern Libya)

The palaeoclimatic evolution of northwestern Libya has been deduced from the study ofthe palustrine and aeolian sediments. The Holocene environmental variations have beenrecognized through geological and stratigraphic surveys and by pollen analysis andmalacofauna content of the sediments. Some organic-rich horizons have been dated usingthe radiocarbon method. The data show that in general, the presence of marshes is linkedwith the period of higher humidity, which began around ca 9.4 ka BP and ended around5.0 ka BP. From ca. 5.0 ka BP up to about 4.4 ka BP, there was a simultaneous presenceof marshes and vegetation of arid climate as a consequence of rainfall in the mountainsand/or a decrease in temperatures. The Holocene wet period was interrupted by two aridspells dated about 8.2 and 5.5-5.4 ka BP. The end of the wet phase must have beengradual. The climatic events that occurred in the Jefara plain seem to be well correlatedwith those identified in Saharan Africa even if the Mediterranean is only one hundredkilometers away.